ORDER

ALLISON CLAIRE, Magistrate Judge.

Plaintiff is a state prisoner at California State Prison Sacramento (CSP-SAC), who proceeds pro se and in forma pauperis with this civil rights action against defendant Correctional Officer (CO) J. McCowan. Presently pending are plaintiff's third and fourth requests for appointment of counsel. See ECF Nos. 27, 32. For the reasons that follow, plaintiff's requests are denied without prejudice.

The court denied without prejudice plaintiff's first and second requests for appointment of counsel. See ECF Nos. 18, 24. The court reasoned that this action presents relatively straightforward claims against only one defendant, and that plaintiff's complaint and briefing indicate he is capable of articulating his claims and arguments and pursuing essential discovery despite his pro se status. Although plaintiff stated that he relied on other inmates to prepare his court filings, the court noted that plaintiff had submitted no documentation to substantiate his alleged educational, mental health, and physical impairments. See ECF No. 18 at 2. Plaintiff has now submitted documentation supporting these allegations.

Plaintiff had the assistance of Unit Field Representative M. Desilets in preparing his fourth request for appointment of counsel. See ECF No. 32 at 5. Plaintiff has submitted documentation demonstrating that he is housed at the Psychiatric Services Unit (PSU) for treatment of mood disorder, antisocial personality disorder, recurring depression and post-traumatic stress disorder (PTSD). See ECF No. 32 at 2, 7. Plaintiff is assigned to the Enhanced Outpatient Program (EOP).1 ECF No. 27 at 5. A May 2015 Inmate Health Assessment form noted that plaintiff was also assigned to the Developmentally Disabled Program but appeared to have "adequate cognitive functioning." ECF No. 27 at 12. However, plaintiff's TABE (Test of Adult Basic Education) score is apparently "O." See ECF No. 27 at 5 ("under 4.0/no TABE"); id. at 9 ("TABE Reading score of 0.0"); id. at 14 (Initial TABE Score 00.0, dated 9/16/2011). Consistently, staff notes from a December 2015 Classification Hearing indicate that plaintiff "did not appear to understand the communication" despite wearing his hearing aid, reiterating in his own words matters that were explained to him, and asking appropriate questions. ECF No. 27 at 5.

Plaintiff is mobility impaired and uses a cane; he wears special shoes and is restricted to bottom bunks in lower tier cells. ECF No. 27 at 13, 14, 16. Plaintiff is sight impaired, which he describes as progressive macular degeneration in his right eye and "thin nerves" in his left eye. ECF No. 32 at 2, 4. Plaintiff wears prescription glasses. ECF No. 27 at 14, 16. Plaintiff is entitled to accommodations under the Americans with Disabilities Act (ADA), and has a permanent chrono requiring special cuffing and waist chains. ECF No. 27 at 14, 16.

Plaintiff again states that he relies on the assistance of other inmates to prepare his legal documents. He asserts that the issues involved in this case are complex and outside his "comprehension and full understanding." ECF No. 27 at 1. Plaintiff states that he is "unable to comprise witnesses, affidavits or statements or to gather discover info." Id. Plaintiff contends that appointed counsel will be necessary at trial to examine and cross-examine witnesses. Plaintiff also asserts that appointment of a neutral medical expert will be required "to explain to the court and jury the extent of plaintiff's injuries and suffering from defendant's constitutional violations." ECF No. 27 at 2.

As plaintiff was previously informed, this court is without authority to require counsel to represent indigent prisoners in Section 1983 cases. Mallard v. United States Dist. Court, 490 U.S. 296, 298 (1989). However, under 28 U.S.C. § 1915(e)(1), this court may request the voluntary assistance of an attorney in exceptional circumstance. See Terrell v. Brewer, 935 F.2d 1015, 1017 (9th Cir. 1991); Wood v. Housewright, 900 F.2d 1332, 1335-36 (9th Cir. 1990). The test for exceptional circumstances requires an evaluation of plaintiff's likelihood of success on the merits of his claims and ability to articulate his claims pro se in light of the complexity of the factual and legal issues presented by his case. See Wilborn v. Escalderon, 789 F.2d 1328, 1331 (9th Cir. 1986); Weygandt v. Look, 718 F.2d 952, 954 (9th Cir. 1983). Circumstances common to most prisoners, such as lack of legal education and limited law library access, do not establish the requisite exceptional circumstances. The burden of demonstrating exceptional circumstances is on the plaintiff. Palmer v. Valdez, 560 F.3d 965, 970 (9th Cir. 2009).

This court must carefully assess these matters in each case because there are far fewer attorneys willing to undertake such representation than the number of requests for appointed counsel filed by prisoners in civil rights cases.

Plaintiff has demonstrated that he has significant mental, emotional and physical disabilities that impair his ability to pursue litigation on his own behalf. Nevertheless, many of plaintiff's personal challenges are shared by other prisoners and are therefore not exceptional within the prison context. Moreover, the factual allegations of this case are succinct2 and plaintiff's legal claims — Eighth Amendment claims for excessive force and deliberate indifference to plaintiff's serious medical needs — are straightforward. See ECF No. 10 at 6-9. Because ultimate resolution of this case will depend on the parties' credibility, the court is unable to conclude at this juncture that plaintiff has a strong likelihood of success on the merits of his claims. Should this case proceed to trial, appointed counsel for plaintiff appears warranted. However, at this juncture,3 and in light of the limited number of available volunteer attorneys, appointment is not clearly warranted. Matters of credibility cannot be determined on summary judgment. Should defendant file a motion for summary judgment, plaintiff should submit all of his evidence in opposition and attempt, to the best of his ability (and/or with the continuing assistance of other inmates), to respond to defendant's arguments in a manner that conforms with the Local Rules. The court will liberally construe plaintiff's filings, as it is required to do. See Thomas v. Ponder, 611 F.3d 1144, 1150 (9th Cir. 2010).

For these reasons, the court finds that plaintiff has not met his burden of demonstrating exceptional circumstances warranting the appointment of counsel at this time.

Plaintiff's request for appointment of a neutral medical expert will also be denied. The purpose of a court-appointed expert under Federal Rule of Evidence 706 is to assist the trier of fact, not to serve as an advocate, and the court retains the authority to appoint a neutral expert witnesses at any time. See Walker v. American Home Shield Long Term Disability Plan, 180 F.3d 1065, 1071 (9th Cir. 1999) ("district court . . . has the discretion to appoint an expert sua sponte under Federal Rule of Evidence 706(a)"); Pedraza v. Jones, 71 F.3d 194, 196 (5th Cir. 1995) ("[t]he plain language of section 1915 does not provide for the appointment of expert witnesses to aid an indigent litigant").

Accordingly, IT IS HEREBY ORDERED that plaintiff's motions for appointment of counsel, ECF Nos. 27, 32, and related request for appointment of a neutral medical expert, are denied without prejudice.