FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

MARIA DE RODRIGUEZ-ECHEVERRIA,           
                      Petitioner,                No. 06-73670
               v.
                                                 Agency No.
                                                 A77-983-920
MICHAEL B. MUKASEY, Attorney
General,                                           OPINION
                    Respondent.
                                         
          On Petition for Review of an Order of the
               Board of Immigration Appeals

                   Argued and Submitted
              May 6, 2008—Pasadena, California

                       Filed July 25, 2008

      Before: Raymond C. Fisher and Richard A. Paez,
    Circuit Judges, and James L. Robart, District Judge.*

                    Opinion by Judge Fisher




 *The Honorable James L. Robart, United States District Judge for the
Western District of Washington, sitting by designation.

                               9333
9336          RODRIGUEZ-ECHEVERRIA v. MUKASEY


                        COUNSEL

Andrew Knapp, Cifuentes Knapp & Associates, Los Angeles,
California, for the petitioner.

Jonathan Robbins (argued), Mona Maria Yousif, James A.
Hunolt, and Peter D. Keisler, Assistant Attorney General,
Department of Justice, Washington, D.C., for the respondent.
              RODRIGUEZ-ECHEVERRIA v. MUKASEY            9337
                         OPINION

FISHER, Circuit Judge:

   Maria de Rodriguez-Echeverria (“Rodriguez”) petitions for
review of a final order of removal, arguing that the Immigra-
tion Judge (“IJ”) erred in failing to suppress her statements,
which she maintains were obtained in violation of Department
of Homeland Security (“DHS”) regulations and were coerced
in violation of the Fifth Amendment’s Due Process Clause.
She also argues that the Board of Immigration Appeals
(“BIA”) abused its discretion by affirming the IJ’s decision
without opinion. We agree that the IJ erred in determining
that Rodriguez was not under arrest at the time she gave her
incriminating statements, and so we remand for the BIA to
determine in the first instance whether her rights under the
regulation were infringed and whether her statements were
freely given.

                     BACKGROUND

   Rodriguez is a native and citizen of Mexico who has been
a legal permanent resident of the United States since October
2002. On the morning of January 11, 2004, she drove from
her home in Anaheim, California to Mexico along with her 7-
year-old U.S. citizen son, Erwin. While in Mexico, Rodriguez
met up with her sister, Socorro Rodriguez (“Socorro”), who
is also a legal permanent resident of the United States. The
three of them returned to the United States together with
Emmanuel Martinez, who is Rodriguez’s and Socorro’s 15-
year-old nephew and a Mexican citizen. Rodriguez testified
that she wanted to take the boy on vacation in the United
States. Emmanuel, however, did not have a visa that would
allow him to enter.

   Border patrol records show that at approximately 5:30 p.m.
on January 11, Rodriguez attempted to cross the border back
into the United States. Rodriguez testified that she was driv-
9338              RODRIGUEZ-ECHEVERRIA v. MUKASEY
ing the car, her sister Socorro was in the front passenger seat
and the two boys were in the back. Rodriguez handed the bor-
der patrol officer her valid green card, Socorro’s valid green
card and her son’s birth certificate. The documentation she
presented for Emmanuel was Soccoro’s son’s U.S. birth cer-
tificate. The border patrol officer became suspicious when
Emmanuel failed to respond appropriately to a question posed
to him and referred the car to secondary inspection. At sec-
ondary inspection, the officers discovered Emmanuel’s true
Mexican identification in one of his bags. The group was then
escorted inside a building, where they were fingerprinted,
photographed and made to remove their belts and shoe laces
and face a wall. At some point a Form G-166 Report of Inves-
tigation was filled out.1 It listed the “date of arrest” as 6:56
p.m. on January 11, 2004, or about an hour and a half after
Rodriguez was referred to secondary inspection.

  The government does not dispute Rodriguez’s account of
events at the border. Rodriguez testified that after several
hours of either waiting around or being questioned, she,
Erwin, Emmanuel and Socorro were put in a locked room
with benches and a toilet. Shortly after two in the morning,
Socorro and Erwin were allowed to leave. Rodriguez said that
she was cold and hungry, having not eaten anything for over
12 hours, but she was not provided with food and was denied
a blanket. At around 3:30 a.m., another officer came on duty
and removed Rodriguez and Emmanuel from the holding cell.
The officer removed cosmetics and other personal items from
Rodriguez’s purse and threw them away, telling her that she
could not keep them at “la grande prision” (the jail) that she
   1
     It is not clear when the officer filled out the form, because it does not
have a time stamp. The date on the form is January 11, 2004. However,
the report says that Socorro was “booked and released,” and Socorro testi-
fied that she was released sometime around 2:00 a.m. on January 12.
Therefore, it seems likely that this form was filled out sometime on or
after January 12. It is not clear how or when the officer obtained the infor-
mation described in the report.
              RODRIGUEZ-ECHEVERRIA v. MUKASEY              9339
would be going to. Rodriguez was then placed in another
holding cell.

   At around 11 a.m., Rodriguez was removed from the hold-
ing cell and taken to another office to give her declaration.
The officers spoke to her in a combination of English and
Spanish; the government does not dispute that the officers did
not inform her that she had a right to an attorney or that her
statements could be used against her. An officer took Rodri-
guez’s tape-recorded statement in Spanish. Rodriguez was
informed that her participation was voluntary and was asked
a series of questions about how Emmanuel was brought to the
border; Rodriguez admitted responsibility for knowingly
bringing Emmanuel into the country with a false birth certifi-
cate. After the interview, another officer prepared a Form I-
213, Notice to Appear, charging Rodriguez with being a
removable alien under 8 U.S.C. § 1182(a)(6)(E)(i), which
makes inadmissible “[a]ny alien who at any time knowingly
has encouraged, induced, assisted, abetted, or aided any other
alien to enter or try to enter the United States in violation of
law.” The Notice to Appear contained a statement in English
informing Rodriguez that her statements may be used against
her and that she has a right to counsel of her choosing. She
was then released on her own recognizance into the United
States.

   At Rodriguez’s merits hearing before the IJ, the govern-
ment sought to introduce the transcript of Rodriguez’s
recorded statement, as well as the I-213 and G-166 forms
describing the substance of Rodriguez’s admissions. Rodri-
guez moved to have her statements suppressed, arguing that
they were obtained in violation of DHS regulations and were
coerced in violation of the Fifth Amendment. Rodriguez sub-
mitted declarations from herself and Socorro, supporting her
contention that the statements were coerced. These affidavits
also stated that it was Socorro, not Rodriguez, who was solely
responsible for providing Emmanuel with the false identifica-
tion document. No other evidence was introduced at the mer-
9340          RODRIGUEZ-ECHEVERRIA v. MUKASEY
its hearing and neither side presented witnesses. The IJ denied
Rodriguez’s motion to suppress, finding that DHS had the
right to detain and question Rodriguez and that her statements
were not coerced. The IJ then found that clear and convincing
evidence established that Rodriguez was removable on the
lodged charge. Rodriguez appealed to the BIA, which
affirmed without opinion. Rodriguez then filed a timely peti-
tion for review with this court.

                         ANALYSIS

   We have jurisdiction under 8 U.S.C. § 1252(a). Because the
BIA issued a streamlined decision, “the IJ’s decision becomes
the BIA’s decision and we evaluate the IJ’s decision as we
would that of the Board.” Lanza v. Ashcroft, 

,
925 (9th Cir. 2004) (internal quotation marks omitted). Ques-
tions of law are reviewed de novo. See Hernandez-Gil v. Gon-
zales, 

, 804 n.1 (9th Cir. 2007). Factual findings
are reviewed for substantial evidence. See Zehatye v. Gon-
zales, 

, 1184-85 (9th Cir. 2006).

                              I.

   [1] Rodriguez argues that the IJ erred in finding that she
was not under arrest at the time she gave her incriminating
statements, and therefore that he erred in finding that she was
not entitled to be informed of her right to counsel and her
right to remain silent as provided by DHS regulations. We
agree that the IJ erred in concluding that Rodriguez was not
under arrest.

  The relevant regulation provides that

    an alien arrested without warrant and placed in for-
    mal proceedings . . . will be advised of the reasons
    for his or her arrest and the right to be represented
    at no expense to the Government . . . . The officer
    will also advise the alien that any statement made
               RODRIGUEZ-ECHEVERRIA v. MUKASEY              9341
    may be used against him or her in a subsequent pro-
    ceeding.

8 C.F.R. § 287.3(c). Another DHS regulation defines an “ar-
rest,” and provides that an officer conducts “[i]nterrogation
and detention not amounting to arrest” when the officer asks
questions, “as long as the immigration officer does not
restrain the freedom of an individual, not under arrest, to walk
away.” 8 C.F.R. § 287.8(b)(1) (emphasis added). If an officer
makes a warrantless arrest, the officer is instructed to “adhere
to the procedures set forth in 8 C.F.R. § 287.3,” including the
requirement that the alien be informed of certain rights. 8
C.F.R. § 287.8(c)(2)(iv).

   Before she was interrogated by immigration officers,
Rodriguez was not told that she had a right to counsel or that
her statements could be used against her in a future proceed-
ing. The IJ found that Rodriguez’s rights under the regulation
were not violated, however, because “Immigration Officers at
the port of entry had the right to detain [Rodriguez] for ques-
tioning both in conjunction with the fact that she was seeking
admission to the United States and in conjunction with the
fact that officers had reasonable suspicion that she may have
been engaging in unlawful activity.” Rodriguez does not dis-
pute that the officers had the right to detain and question her,
nor does she dispute that they had the right to arrest her with-
out a warrant. Rather, her sole contention is that the officers
at the border placed her under warrantless arrest shortly after
her arrival at secondary inspection, and that she was therefore
entitled to be told of her rights as provided by § 287.3(c) prior
to questioning, but was not.

   [2] As the government has now effectively conceded, the
IJ erred in concluding that Rodriguez was merely detained, as
opposed to arrested, at the time of her interrogation. The Form
G-166 Report of Investigation clearly shows that Rodriguez’s
“date of arrest” was 6:56 p.m. on January 11, or about an hour
and a half after she was referred to secondary inspection and
9342          RODRIGUEZ-ECHEVERRIA v. MUKASEY
more than 16 hours before she was asked to give her recorded
statement. Further, Rodriguez was placed in a locked room
overnight and made to remove her shoes and belt, actions
which undoubtedly “restrain the freedom of an individual . . .
to walk away.” See 8 C.F.R. § 287.8(b). Rodriguez’s over-
night detention at the border therefore qualifies as a warrant-
less arrest under DHS regulations. The arresting officers were
accordingly obligated to comply with the requirements of
§ 287.3.

   Because the IJ erroneously concluded that § 287.3 did not
apply, the BIA on remand should determine in the first
instance whether § 287.3 requires the officers to warn Rodri-
guez prior to interrogation that she had a right to counsel and
that her statements could be used against her, and if so,
whether her statements should be suppressed. Any failure to
comply with the regulations may also bear on the question of
whether her statements were voluntary under the Fifth
Amendment, and so we remand this question as well. See
Navia-Duran v. INS, 

, 810 (1st Cir. 1977) (not-
ing that “[i]f the INS had complied with its own regulation,”
then “the atmosphere of coercion would have vanished”
because the alien would have been fully aware of her rights);
see also Matter of Garcia, 17 I. & N. Dec. 319, 321 (BIA
1980).

   [3] The government urges us to affirm the IJ on a number
of alternate grounds, including that the failure to provide the
warnings did not violate § 287.3, that the proper remedy for
a violation of § 287.3 would not be the suppression of Rodri-
guez’s statements, and that the admission of her statements,
even if in error, was harmless because there was other evi-
dence in the record to sustain the charge of removability. It is
well established, however, that “this court cannot affirm the
BIA on a ground upon which it did not rely.” Navas v. INS,

, 658 n.16 (9th Cir. 2000); see also Andia v. Ash-
croft, 

, 1184 (9th Cir. 2004) (“In reviewing the
decision of the BIA, we consider only the grounds relied upon
              RODRIGUEZ-ECHEVERRIA v. MUKASEY                9343
by the agency. If we conclude that the BIA’s decision cannot
be sustained upon its reasoning, we must remand to allow the
agency to decide any issues remaining in the case.”). We
decline to speculate as to how the IJ may have ruled on these
questions and remand so that the agency may consider them
in the first instance.

                              II.

   [4] Rodriguez also argues that the BIA erred by summarily
affirming, or streamlining, her appeal. DHS regulations pro-
vide that the BIA may streamline a case if it determines that

    the result reached in the decision was correct; that
    any errors in the decision under review were harm-
    less or nonmaterial; and that (A) The issues on
    appeal are squarely controlled by existing Board or
    federal court precedent and do not involve the appli-
    cation of precedent to a novel factual situation; or
    (B) The factual and legal issues raised on appeal are
    not so substantial that the case warrants the issuance
    of a written opinion in the case.

8 C.F.R. § 1003.1(e)(4)(i). We have jurisdiction to determine
whether the BIA complied with its own regulations in decid-
ing to streamline. See Chen v. Ashcroft, 

, 1087-
88 (9th Cir. 2004).

   Because we conclude that we must remand to the agency
based on its erroneous fact-finding, we need not reach the
question of whether the BIA abused its discretion by stream-
lining Rodriguez’s appeal. We note, however, that the BIA
has not issued a published opinion interpreting the regulation
at issue here, § 287.3, since 1980. See Matter of Garcia-
Flores, 17 I. & N. Dec. 325 (BIA 1980). The regulation has
been amended several times in the intervening years. Whereas
the 1977 version considered by the BIA in Garcia-Flores
stated that “[a]n alien arrested without warrant of arrest shall
9344             RODRIGUEZ-ECHEVERRIA v. MUKASEY
be advised” of the reason for his arrest, his right to counsel
and that any statement may be used against him, the current
version of the regulation states that “an alien arrested without
warrant and placed in formal proceedings” shall be advised
of this same information. Compare 8 C.F.R. § 287.3 (1977)
with 8 C.F.R. § 287.3(c) (2008) (emphasis added). DHS also
added a new regulation in 1994, which purports to limit the
alien’s ability to assert certain rights.2 Although the govern-
ment argues that the plain language of § 287.3 indicates that
arrested aliens have no right to receive regulatory warnings
until formal proceedings are brought, the U.S. Customs and
Border Protection appears to have reached a contrary interpre-
tation. See U.S. Customs and Border Protection, Inspector’s
Field Manual 163 (Charles M. Miller, ed.) (2006) (suggesting
that arrested aliens should “be given two hours to contact
counsel before questioning can proceed”).3

   Given the considerable changes to the law since the BIA
last interpreted this regulation and the apparent disagreement
among government agencies as to what § 287.3 requires, we
direct the BIA to consider carefully on remand its decision to
streamline this case. Certainly it cannot be said that “[t]he
issues on appeal are squarely controlled by existing Board or
federal court precedent,” nor can it be said that the issues
presented are “not . . . substantial,” when they potentially
affect the conduct of every immigration officer and the rights
of all aliens subject to arrest and interrogation. See 8 C.F.R.
§ 1003.1(e)(4)(i). One of the reasons supporting the issuance
of a three-member BIA opinion is “[t]he need to establish a
precedent construing the meaning of laws, regulations, or pro-
  2
    This regulation provides in relevant part that “[t]hese regulations do
not, are not intended to, shall not be construed to, and may not be relied
upon to create any rights, substantive or procedural, enforceable at law by
any party in any matter, civil or criminal.” 8 C.F.R. § 287.12.
  3
    The CBP Field Inspector’s Manual is available at http://
www.srwlawyers.com/Portals/0/CBP%20Inspectors%20Field%20
Manual.pdf.
                  RODRIGUEZ-ECHEVERRIA v. MUKASEY                      9345
cedures.” 8 C.F.R. § 1003.1(e)(6)(ii). We believe that such
guidance is called for here.

                            CONCLUSION

  Because the IJ erroneously concluded that Rodriguez was
not under arrest at the time she was interrogated, we remand
so that the agency may consider in the first instance whether
Rodriguez’s rights under § 287.3 were violated and whether
her statements were offered voluntarily.4

   GRANTED, REMANDED.




  4
   Because we grant the petition and remand, we decline to reach any of
Rodriguez’s other arguments in favor of granting the petition, including
that the IJ erred by allegedly refusing to allow Rodriguez to testify or that
he erred by admitting an allegedly improperly certified page of the I-213.