WESTMINSTER, Colo. (CBS4) – Westminster police are looking for 30-year-old James Naulls, Jr. after they say he severely beat his ex-wife. They say he also strangled her.

James Arthur Naulls, Jr. (credit: Westminster)

Officers responded to a 911 call made by the victim on Friday afternoon. They say the call indicated a 33-year-old woman fell, but officers determined there was suspicious circumstances to her injuries.

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She was taken to an undisclosed hospital where they say she has serious, life-threatening injuries.

James Arthur Naulls, Jr. (credit: Westminster)

Police say Naulls cut off his ankle monitor he received for a separate domestic violence incident from November of 2019. In that case, he was pleaded not guilty to assault, strangulation, false imprisonment and violation of a protection order.

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Officers say they believe Naulls has called various local hospitals to find the victim.

There is an active arrest warrant for Naulls on charges of attempted first degree murder and first degree assault.

James Arthur Naulls, Jr. (credit: Westminster)

Authorities describe Naulls as having very distinct facial and neck tattoos. He is 5-foot-7 and weighs 190 pounds; he has brown eyes and a shaved head.

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Those with more information about Naulls are asked to call (303-658-4360). You can remain anonymous by calling Crime Stoppers at 720-913-7867. A reward of up to $2000 is available for any information that leads to his capture.