This is an appeal from the district court's denial of the Government's "Motion for Determination of Admissibility of Evidence" and further order that "all evidence concerning the identity and participation of defendant HUMPHRIES in this case is suppressed." We affirm in part, reverse in part and remand.

On April 20, 1977, an indictment was returned against appellee Richard Humphries and four others and was filed in the United States District Court for the District of Arizona. The indictment charged each of the defendants with conspiracy to import marijuana, conspiracy to distribute marijuana, importation of marijuana, and attempt to possess marijuana with intent to distribute it.1

Humphries moved for an order suppressing his identity "as a defendant in this matter and any and all other physical evidence and statements obtained as a result of the illegal arrest of (Humphries) in this matter." Judge Muecke heard the argument on Humphries' motion and granted that motion on January 26, 1978.

On February 3, the Government moved for a "Determination of Admissibility of Evidence." This second motion was heard by Judge Davies, who denied it on February 17, ordering that

all evidence concerning the identity and participation of defendant HUMPHRIES in this case is suppressed for the reason that the Plaintiff has not shown that any of said evidence is derived from a source other than the illegal arrest of defendant HUMPHRIES.

The Government appeals from this second order. On May 25, two members of this court denied Humphries' motion to dismiss the appeal for failure to file timely notice of appeal.2

Humphries contends that this court is without jurisdiction over the United States' appeal in this case. He urges that the Government has attempted to circumvent the requirements of 18 U.S.C. § 3731 by moving for a "Determination of Admissibility" and appealing within 30 days of that order, but more than 30 days after the district court's initial decision on Humphries' suppression motion. We hold that we have jurisdiction to hear this appeal.

The courts often have been called upon to construe 18 U.S.C. § 3731, the Criminal Appeals Act.3 Of their decisions, Professors Wright and Miller have said:

Appeals (under § 3731) are clearly allowed from interlocutory orders suppressing or excluding evidence or requiring the return of property, in marked contrast to the rules governing appeals by criminal defendants or witnesses.

15 Wright & Miller, Federal Practice and Procedure § 3919, at 656 (footnote omitted); See, e. g., United States v. Donovan, 429 U.S. 413, 421 n.8, 97 S. Ct. 658, 50 L. Ed. 2d 652 (1977); United States v. Martinez-Fuerte, 514 F.2d 308, 310 (9th Cir. 1975), Rev'd on other grounds, 428 U.S. 543, 96 S. Ct. 3074, 49 L. Ed. 2d 1116 (1976).

Section 3731 is broadly construed, for its legislative history makes it clear that

"Congress intended to remove all statutory barriers to Government appeals and to allow appeals whenever the Constitution would permit."

United States v. Martin Linen Supply Co., 430 U.S. 564, 568, 97 S. Ct. 1349, 1353, 51 L. Ed. 2d 642 (1977), Quoting United States v. Wilson, 420 U.S. 332, 337, 95 S. Ct. 1013, 43 L. Ed. 2d 232 (1975).4 The only limitation on Government appeals under § 3731 is the double jeopardy clause of the United States Constitution. United States v. Rojas, 554 F.2d 938, 941 (9th Cir. 1977), Supplemented, 574 F.2d 476 (9th Cir. 1978); See note 4 Supra.

Humphries contends that the Government's appeal is not properly before this court because it is a "Motion to Determine the Admissibility of Evidence" and not within the express language of § 3731. Humphries does not argue that the Government's appeal here violates the constitutional prohibition against placing him twice in jeopardy.

To hold that the order here is not appealable under § 3731 because a denial of a "Motion to Determine the Admissibility of Evidence" is not a " decision . . . suppressing or excluding evidence" is to focus on the title of the Government's motion rather than the effect of the district court's order. Such an approach flies in the face of the intent of Congress and is contrary to consistent judicial authority. Section 3731 must be construed broadly; a Government appeal should not be rejected on a hypertechnical jurisdictional ground. Thus, we refuse to limit the Government's right to appeal under § 3731 solely because of the title of its motion. Instead, we "focu(s) on the effect of the ruling sought to be appealed." United States v. Martin Linen Supply Co., 534 F.2d 585, 587 n.3 (5th Cir. 1976), Aff'd,430 U.S. 564, 97 S. Ct. 1349, 51 L. Ed. 2d 642 (1977); See United States v. Wilson, 420 U.S. 332, 95 S. Ct. 1013.

Humphries alternatively argues that the Government has in fact appealed from the January 26 order of Judge Muecke; that the Government's "Motion to Determine the Admissibility of Evidence" and its appeal from Judge Davies' order denying that motion were merely an attempt to circumvent the time limits on appeals under § 3731.

Judge Muecke's order granted Humphries' motion that

the identity of JOHN RICHARD HUMPHRIES as a defendant in this matter and any and all other physical evidence and statements obtained as a result of the illegal arrest of the defendant (be suppressed) in this matter.

His decision did not elaborate on what evidence was covered by his order; the opinion merely addressed the illegality of the arrest or detention of Humphries.

The Government made its "Motion to Determine the Admissibility of Evidence" eight days after Judge Muecke entered his order. The Government did not challenge Judge Muecke's order; instead it sought only a decision on whether "certain identification evidence concerning defendant HUMPHRIES" was admissible under the previous order. A careful review of the transcripts and record in this case indicates that there was considerable confusion as to the scope of Judge Muecke's ruling5 and that the testimony presented in the hearing before Judge Davies on the Government's motion was significantly different from that presented to Judge Muecke on the previous motion.6

Given the confusion surrounding the earlier order, and that the Government indeed presented different evidence in the hearing on its motion, we cannot agree with Humphries that the Government's actions were calculated to circumvent the requirements of the Criminal Appeals Act.7 The Government's appeal is one from Judge Davies' order suppressing all evidence relating to Humphries. Such an appeal is proper under § 3731 and was timely filed.8 We thus have jurisdiction over this appeal.

Judge Davies ordered that all evidence concerning Humphries' identity and participation in the marijuana smuggling operation in this case be suppressed. The Government appeals from this order only as to three categories of evidence: (1) the testimony of Frank Sisto; (2) evidence gained as the result of the surveillance of a residence in Scottsdale, Arizona; and (3) the testimony of James "Bullet" Thompson, the alleged pilot of the crashed marijuana-laden plane involved in this case.

Frank Sisto testified that on the evening of October 23, 1976, he met two strangers at the home of his daughter, just north of San Carlos, Arizona.9 One of the men introduced himself as "Tony" and explained that their truck had broken down about three miles north of the residence. He asked to use the telephone to call his wife to pick them up. When Sisto gave his permission to use the phone, "Tony" asked where the best place to wait for his wife would be. Sisto suggested the San Carlos police station but "Tony" said that he did not wish to wait there. Sisto then suggested the tribal store in San Carlos and offered to give the two men a ride to that point. "Tony" accepted Sisto's offer. After taking the two men to the store, Sisto called the police station because he was "worried" and had a "funny feeling" about them.

Sisto's message was passed along to Bureau of Indian Affairs (BIA) Special Agent Little Whiteman, who was investigating a downed aircraft loaded with marijuana near the area where Sisto initially saw the two men. Little Whiteman ordered one of his officers to go to the tribal store to see if the two were still there. Upon receiving word that the two men were still at the tribal store, Little Whiteman ordered them brought in for questioning. This detention was held an illegal arrest by Judge Muecke.10

In court Sisto pointed to Humphries as one of the men to whom he had given a ride. His testimony and identification were based solely on his contact with Humphries and his codefendant, Richardo Rubio ("Tony") prior to the unlawful arrest. It is not in any way a "fruit" of that unlawful arrest. See United States v. Williams, 436 F.2d 1166, 1170 (9th Cir. 1970), Cert. denied, 402 U.S. 912, 91 S. Ct. 1392, 28 L. Ed. 2d 654 (1971). Thus, we reverse Judge Davies' order insofar as it suppresses Sisto's testimony.11

Agent Little Whiteman testified before Judge Davies concerning the discovery of a downed airplane containing a large quantity of marijuana. He related the discovery of papers in the plane and his follow-up investigation which led to the identification of James "Bullet" Thompson as the pilot of that aircraft. This information, along with information obtained during the illegal arrest and detention of Humphries (name, address, fingerprints and photograph), was eventually passed to Agent Stine of the Arizona Department of Public Safety, Narcotics Enforcement Division (DPS). Little Whiteman also gave Stine the description and license number of a beige 1971 Chevrolet Monte Carlo that he had stopped near the crash site.

On the basis of this information, Stine obtained a driver's license photograph of Humphries and proceeded to attempt to locate the pilot, Thompson, by investigating a Scottsdale address called by Thompson while he was in Chicago. Arriving at the Scottsdale residence, Stine noticed a beige Monte Carlo in the driveway. Unable to read the license plate from the street, he drove up the driveway and positively identified the auto as the one stopped by Little Whiteman. He also noticed two persons at the residence while in the driveway, one of whom he identified as Humphries from the driver's license photo in his possession.

Relying on the information from Little Whiteman and his observations while in the driveway, Stine ordered around-the-clock surveillance of the Scottsdale address. During the course of their stakeout, DPS agents photographed Humphries and others at the residence.

In the hearing before Judge Davies, the Government stipulated that it would not introduce evidence concerning the identification of Humphries made by Stine in the driveway of the Scottsdale residence. Therefore, we are concerned only with the admissibility of the license number of the Monte Carlo and the photographs and other evidence garnered as a result of the surveillance of the residence.

1. Identification of the Automobile in Scottsdale

The license plate number and description of an automobile which Stine had when he spotted the car in Scottsdale and entered the driveway to check the license plate of that car was derived from a stop of a vehicle by BIA agents. The legality of that stop is unchallenged in this case. Moreover, the stop was wholly unrelated to the illegal arrest of Humphries. Thus, the BIA information concerning the auto stopped near the crash site was untainted; its use by Stine was not improper.

However, Humphries points out that Stine matched the license plate number of the car in Scottsdale with the number in his possession only by trespassing onto a private driveway. Judge Davies' order and opinion, holding as it did that the license number identification was tainted by Humphries' illegal arrest, did not reach Humphries' trespass theory. Since we have concluded that the illegal arrest of Humphries did not taint the BIA information concerning the auto stopped near the crash site, we must reach this claim.

In Katz v. United States, 389 U.S. 347, 88 S. Ct. 507, 19 L. Ed. 2d 576 (1967), the Supreme Court noted that "(t)he premise that property interests control the right of the Government to search and seize has been discredited." Id. at 353, 88 S.Ct. at 512, Quoting Warden v. Hayden, 387 U.S. 294, 304, 87 S. Ct. 1642, 18 L. Ed. 2d 782 (1967). It concluded that "the Fourth Amendment protects people, not places." Id. at 351, 88 S.Ct. at 511; See Warden v. Hayden, 387 U.S. at 304, 87 S.Ct. at 1648 ("the principal object of the Fourth Amendment is the protection of privacy rather than property"). "(T)he reach of (the Fourth) Amendment cannot turn upon the presence or absence of a physical intrusion . . . ." Katz v. United States, 389 U.S. at 353, 88 S. Ct. at 512.

Only when there is an invasion of some reasonable expectation of privacy can police action constitute a search subject to the strictures of the fourth amendment. See United States v. Santana, 427 U.S. 38, 42, 96 S. Ct. 2406, 49 L. Ed. 2d 300 (1976); Katz v. United States, 389 U.S. at 349-53, 88 S. Ct. 507. Although a driveway may be private under common law notions of property, it may not be for purposes of the fourth amendment. See United States v. Santana, 427 U.S. at 42, 96 S. Ct. 2406 (doorway of private home a "public place" where visible from street); United States v. Hersh, 464 F.2d 228, 230 (9th Cir. 1972) (officers going upon front porch of house and looking into window did not violate fourth amendment privacy rights).

Considering all of the circumstances surrounding Stine's entry into the driveway and identification of the Monte Carlo as the automobile previously stopped by BIA agents near the crash site, we conclude that the entry and identification did not violate any reasonable expectation of privacy held by Humphries. The auto was visible from the street. It does not appear from the record that the driveway was enclosed by a fence, shrubbery or other barrier. Stine did not move bushes or other objects in order to make his observations. See United States v. Hersh, 464 F.2d at 230; United States v. Davis, 327 F.2d 301, 303-04 (9th Cir. 1964). Moreover, a license plate is affixed on an automobile for the very purpose of allowing identification of it by law enforcement agencies and others.12

Thus, Stine's conduct did not constitute a search subject to fourth amendment limitations. His testimony regarding his identification of the car was improperly suppressed. We reverse Judge Davies's order insofar as it suppresses that testimony.

2. Photographs and Other Surveillance Evidence

Agent Stine testified that the surveillance of the Scottsdale residence was undertaken because of his identification of Humphries and the automobile while he was in the driveway of that address. The surveillance and all evidence derived from it is tainted by the illegal arrest of Humphries.

In Wong Sun v. United States, the Supreme Court announced the appropriate test of whether evidence is inadmissible as the fruit of unlawful police action:

Rather, the more apt question in such a case is "whether, granting establishment of the primary illegality, the evidence to which instant objection is made has been come at by exploitation of that illegality or instead by means sufficiently distinguishable to be purged of the primary taint."

371 U.S. 471, 488, 83 S. Ct. 407, 417, 9 L. Ed. 2d 441 (1963), Quoting Maguire, Evidence of Guilt 221 (1959). Exploitation of illegalities is the focus of the fruits doctrine for the reason that the exclusionary rule is aimed at deterring police conduct in violation of the fourth amendment "in the only effectively available way by removing the incentive to disregard it." Stone v. Powell, 428 U.S. 465, 484, 96 S. Ct. 3037, 3047, 49 L. Ed. 2d 1067 (1976), Quoting Elkins v. United States, 364 U.S. 206, 217, 80 S. Ct. 1437, 4 L. Ed. 2d 1669 (1960).

Concern for fourth amendment rights must be balanced against the costs of the exclusionary rule, for

(a)pplication of the rule . . . deflects the truthfinding process and often frees the guilty. The disparity in particular cases between the error committed by the police officer and the windfall afforded a guilty defendant by application of the rule is contrary to the idea of proportionality that is essential to the concept of justice. Thus, although the rule is thought to deter unlawful police activity in part through the nurturing of respect for Fourth Amendment values, if applied indiscriminately it may well have the opposite effect of generating disrespect for the law and administration of justice.

Id. at 490-91, 96 S.Ct. at 3050 (footnotes omitted).

Balancing our concern for the protection of Humphries' fourth amendment rights against our concern for the truth, we find that the exclusionary rule and the fruits of the poisonous tree doctrine bar the use of any and all evidence gained as a result of the surveillance of the Scottsdale residence. Stine exploited the illegal arrest of Humphries when he used information gathered during Humphries' detention to identify Humphries in Scottsdale. That identification played a large part in Stone's ordering the stakeout of that residence. Thus, the road from the illegal actions of the BIA to the evidence gained by surveilling was short and straight. See United States v. Ceccolini, 435 U.S. 268, 275, 98 S. Ct. 1054, 55 L. Ed. 2d 268 (1978). In such a case, the deterrence of the exclusionary rule is required, and the public's interest in convicting lawbreakers must be subordinated to fourth amendment interests. We therefore find that Judge Davies did not err in suppressing the photographs and other evidence from the surveillance.

James "Bullet" Thompson was located by Agent Stine from information discovered by BIA agents investigating the crashed airplane near San Carlos.13 There was no taint from the illegal arrest attaching to Stine's location of Thompson. Once located, however, Thompson only implicated Humphries in the marijuana smuggling operation upon being asked specifically about him. And Stine questioned Thompson specifically about Humphries only because of information tainted by the illegal arrest.14

In United States v. Ceccolini, the Supreme Court held that the taint of unlawful police action could be dissipated by the exercise of free will by a witness. The Court said

Evaluating the standards for application of the exclusionary rule to live-witness testimony in light of this balance, we are first impelled to conclude that the degree of free will exercised by the witness is not irrelevant in determining the extent to which the basic purpose of the exclusionary rule is advanced by its application. This is certainly true when the challenged statements are made by a putative defendant after arrest, Wong Sun (v. United States, 371 U.S. at 491, 83 S. Ct. 407); Brown v. Illinois, (422 U.S. 590, 603, 95 S. Ct. 2254, 45 L. Ed. 2d 416 (1975)), and A fortiori it is true of testimony given by nondefendants.

435 U.S. at 276, 98 S. Ct. at 1060. Thus, a distinction was made between the "live-witness" testimony of a potential co-defendant and that of a witness not arrested and not implicated in the criminal activities at issue. Additionally, the Court stated that an exercise of free will by a witness may dissipate the taint of unlawful police action only where "any statements (made by the witness) are truly the product of detached reflection and a desire to be cooperative." Id.

In this case, it is clear that Thompson was implicated in the marijuana smuggling operations: he was the alleged pilot of the marijuana-carrying airplane. Moreover, Thompson answered Stine's questions as part of a "plea agreement." "Under such circumstances it is unreasonable to infer that (Thompson's) response (to Stine's questions) was sufficiently an act of free will to purge the primary taint . . . ." Wong Sun v. United States,371 U.S. at 486, 83 S. Ct. at 416. Therefore, the testimony of Thompson concerning Humphries and his part in the criminal endeavor is tainted and was properly suppressed.15

In sum, we affirm so much of Judge Davies' order, as suppresses the photographs taken during, and other evidence obtained through, the surveillance of the Scottsdale residence. We also affirm that portion of the order suppressing Thompson's testimony concerning the identity and participation of Humphries in the marijuana smuggling operation. We reverse as to Sisto's testimony, which is admissible and as to evidence concerning the license number of the car discovered by Stine at the Scottsdale residence. We remand for further proceedings not inconsistent with this opinion.

AFFIRMED IN PART, REVERSED IN PART, REMANDED FOR FURTHER PROCEEDINGS.