MEMORANDUM**

John Roy Garrettson and Donna Kathleen Garrettson appeal the district court’s summary judgment in favor of all defendants on their excessive use of force claims, and the district court’s denial of their motion to amend to add a claim of unlawful interrogation. We review de novo the district court’s grant of summary judgment, Clicks Billiards, Inc. v. Sixshooters, Inc., 251 F.3d 1252, 1257 (9th Cir. 2001), and we review for abuse of discretion the district court’s denial of leave to amend. Chappel v. Laboratory Corp., 232 F.3d 719, 725 (9th Cir. 2000). We affirm in part, reverse in part, and remand.

The district court dismissed Mrs. Garrettsoris excessive use of force claim based upon its determination that she failed to identify the individual officers responsible for the alleged use of force. In opposition to defendants’ motion for summary judgment, however, Mrs. Garrettson submitted her own deposition testimony, wherein she identified Agent McGuckin as one of three officers who was in the room with her for more than an hour and a half, during which time she complained that the handcuffs were too tight, were causing her pain, and requested that they be loosened. A genuine issue of material fact exists as to whether Agent McGuckin participated in what Mrs. Garrettson alleges to have been an excessive use of force. See LaLonde v. County of Riverside, 204 F.3d 947, 959 (9th Cir. 2000) (holding that tight handcuffing can constitute excessive force where the use of force was not objectively reasonable under the circumstances); Cunningham v. Gates, 229 F.3d 1271, 1289 (9th Cir. 2000) (as amended) (quoting United States v. Koon, 34 F.3d 1416, 1447 n. 25 (9th Cir. 1994), rev’d on other grounds, 518 U.S. 81, 116 S.Ct. 2035, 135 L.Ed.2d 392 (1996)) (“police officers have a duty to intercede when their fellow officers violate the constitutional rights of a suspect or other citizen.”). Thus, we reverse the district court’s entry of summary judgment on this claim, as well as the dismissal of the related state law assault and battery *109and emotional distress claims, and remand for further proceedings.

The district court did not abuse its discretion, however, when it denied Mrs. Garrettson leave to amend to add a claim for unlawful interrogation.1 The unlawful interrogation claim was based upon facts and theories that were known, or should have been known, to Mrs. Garrettson at the time this case was filed. By the time Mrs. Garrettson sought leave to amend to allege the unlawful interrogation claim, discovery had been completed and pretrial proceedings were ready to commence. The district court did not err in denying Mrs. Garrettson leave to amend at that late date. See Kaplan v. Rose, 49 F.3d 1363, 1370 (9th Cir. 1994).

AFFIRMED in part, REVERSED in part, and REMANDED for further proceedings on Donna Kathleen Garrettson’s § 1983 claim for excessive use of force, and her state claims for assault, battery and emotional distress. The parties shall bear their own respective costs for this appeal.